Sitecore 9 XP1 implementations establish two key Windows Services supporting xConnect (that are created as Windows Services via the SIF, but other options exist…. more on that later). These are the Sitecore Marketing Automation Engine and Sitecore XConnect Search Indexer components. Each has distinct responsibilities in ensuring that xConnect properly functions so if xConnect is not working or you plan to uninstall Sitecore 9 (services will need to be stopped and removed), please check the Windows Services for the display names of “Sitecore Marketing Automation Engine – xConnectMarketingAutomationOperations-marketingautomationservice” or “Sitecore XConnect Search Indexer – xConnectCollectionSearch-indexworker”.

Per the Sitecore Documentation, the functional aspects are as follows: